The present invention relates to a stencil printer capable of printing an image on a paper or similar recording medium with a master wrapped around its ink drum. More particularly, the present invention relates to a stencil printer including a power save mode for saving power when it is not used.
A digital stencil printer is conventional which uses a laminate thermosensitive stencil made up of a thermoplastic resin film and a porous support adhered to each other. The printer includes a thermal head for selectively perforating, or cutting, the resin film of the stencil with heat in accordance image data. After the perforated stencil or master has been wrapped around an ink drum, ink feeding means arranged in the drum feeds an adequate amount of ink to the inner periphery of the drum. A press roller, press drum or similar pressing member presses a paper or similar recording medium against the ink drum so as to transfer the ink from the drum to the paper via the porous portion of the drum and the perforations of the master. As a result, an image represented by the image data is printed on the paper. A modern stencil printer is capable of performing a continuous sequence including master making, used master discharging, paper feeding and printing steps. This, coupled with the increasing resolution and reducing performance cost, has recently motivated users of the kind producing, say, ten or more copies at a time to use the stencil printer in place of a copier.
Now, it is not unusual that a stencil printer or a copier is simply left unused over a long period of time with its power switch turned on, meaning that the actual operation time thereof is short. Even when the printer or the copier is unused, power is wastefully fed to its various drivelines, sensors, and a control panel. To solve this problem, the power switch may be turned off while the printer or the copier is not used. However, a heater for fixing a toner image is essential with the copier. Should power supply to the heater be turned off, it would take several minutes for the heater to be again warmed up to its operative temperature, delaying the first print time.
In light of the above, Japanese Patent Publication No. 5-31141, for example, discloses a copier having a power save mode for saving power when it is not used.
On the other hand, it is a common practice with a stencil printer, which does not need the above heater, to turn off its power switch when the printer is unused. This, however, brings about the following problem to be solved. In a stencil printer capable of continuously performing master making, used master discharging, paper feeding and printing steps, sections for executing such steps include a plurality of sensors for monitoring, e.g., the size of documents and that of papers, the position of the leading edge of a master, the position of an ink drum, and the position of a compresser for compressing a used master removed from the ink drum. It follows that every time the power switch is turned on, various members including the ink drum and compressor must be returned to their home positions all over again, delaying the first print time by about several ten seconds.
A section included in the stencil printer for feeding papers has traditionally been implemented by a fixed size system or a cassette system. Likewise, a section for discharging the paper or printing has conventionally included side fences which are moved by hand in matching relation to a paper size. Japanese Patent Laid-Open Publication No. 5-124737, for example, proposes a paper feeding system capable of sensing the size and the remaining amount of papers and automatically replenishing and feeding the papers. Also, Japanese Patent Laid-Open Publication No. 10-1254, for example, teaches a paper discharging section capable of automatically moving the side fences in matching relation to a paper size. These automatic paper feed and paper discharge schemes, however, aggravate power consumption when the stencil printer is not used.
Further, a personal computer, sorter or similar peripheral unit is often connected to the stencil printer for causing the printer to operate by sending image data via the peripheral unit. In this condition, maintaining the power switch of the printer turned off is not practical, and a configuration for saving power in the stand-by state of the printer is desired.
Technologies relating to the present invention are also disclosed in, e.g., Japanese Patent Laid-Open Publication Nos. 6-293175, 7-143746, 7-186492, and 8-251317.
It is therefore an object of the present invention to provide a stencil printer having a power save mode for saving power when it is in a stand-by state, and preventing the first printing time from being delayed when it recovers from the power save mode.
In accordance with the present invention, a stencil printer for printing an image on a recording medium with a master wrapped around its ink drum and having a power save mode for saving power when it is not used includes a storing section for storing the conditions of the printer when the power save mode is selected. When the power save mode is selected, a comparing section compares the conditions stored in the storing section and the current conditions of the printer.
Also, in accordance with the present invention, a printing method for causing a stencil printer to print an image on a recording medium with a master wrapped around an ink drum, and including a power save mode for saving power when the printer is not used includes the steps of storing the conditions of the printer when the power save mode is selected, and comparing, when the power save mode is cancelled, the conditions stored and the current conditions of the printer.